// Copyright 2019 The Prometheus Authors// Licensed under the Apache License, Version 2.0 (the "License");// you may not use this file except in compliance with the License.// You may obtain a copy of the License at//// http://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.// See the License for the specific language governing permissions and// limitations under the License. package util import (	"strconv") // TODO(mdlayher): util packages are an anti-pattern and this should be moved// somewhere else that is more focused in the future. // A ValueParser enables parsing a single string into a variety of data types// in a concise and safe way. The Err method must be invoked after invoking// any other methods to ensure a value was successfully parsed.type ValueParser struct {	v   string	err error} // NewValueParser creates a ValueParser using the input string.func NewValueParser(v string) *ValueParser {	return &ValueParser{v: v}} // Int interprets the underlying value as an int and returns that value.func (vp *ValueParser) Int() int { return int(vp.int64()) } // PInt64 interprets the underlying value as an int64 and returns a pointer to// that value.func (vp *ValueParser) PInt64() *int64 {	if vp.err != nil {		return nil	} 	v := vp.int64()	return &v} // int64 interprets the underlying value as an int64 and returns that value.// TODO: export if/when necessary.func (vp *ValueParser) int64() int64 {	if vp.err != nil {		return 0	} 	// A base value of zero makes ParseInt infer the correct base using the	// string's prefix, if any.	const base = 0	v, err := strconv.ParseInt(vp.v, base, 64)	if err != nil {		vp.err = err		return 0	} 	return v} // PUInt64 interprets the underlying value as an uint64 and returns a pointer to// that value.func (vp *ValueParser) PUInt64() *uint64 {	if vp.err != nil {		return nil	} 	// A base value of zero makes ParseInt infer the correct base using the	// string's prefix, if any.	const base = 0	v, err := strconv.ParseUint(vp.v, base, 64)	if err != nil {		vp.err = err		return nil	} 	return &v} // Err returns the last error, if any, encountered by the ValueParser.func (vp *ValueParser) Err() error {	return vp.err}